1. Field of the Invention
The present invention relates to a plasma lighting system for avoiding communication interference with an electronic device, in particular, a wireless local area network (WLAN) device, using the same frequency band.
2. Description of the Related Art
In general, a plasma lighting system emits light by converting a luminous material (or an emitting material) encapsulated in an electrodeless bulb into plasma by using microwave energy generated from a microwave generation unit such as a magnetron. The plasma lighting system using an electrodeless bulb without an electrode has a long life span or is semi-permanent, and light emitted from the electrodeless bulb is tinged with light as good as natural light.
The plasma lighting system generally includes a magnetron generating microwave, an electrodeless bulb charged with a luminous material to generate light by using the microwave delivered from the magnetron, a resonator accommodating the electrodeless bulb and resonating the microwave delivered from the magnetron, and a waveguide connecting the magnetron and the resonator to deliver the microwave generated by the magnetron to the resonator.
In the plasma lighting system, microwave generated from the magnetron is delivered to the resonator through the waveguide, and as the microwave introduced into the resonator is resonated in the resonator, the luminous material of the electrodeless bulb is excited. Then, the luminous material charged in the electrodeless bulb is converted into plasma to generate light, and the light is irradiated to a front side by a reflector installed at a rear side of the electrodeless bulb.
Meanwhile, the related art plasma lighting system is designed by using a magnetron having a resonance frequency of 2450 MHz, causing channel interference with electronic devices, such as the WLAN, a microwave oven, RFID, Bluetooth™, and the like, using 2.4 GHz to 2.5 GHz band. In particular, the WLAN is one of communication network schemes, which wirelessly performs communication between connectors by using a radio frequency (RF). According to IEEE standard, WLAN uses microwave of 2.4 GHz, 5 GHz, or the like. As shown in FIG. 14, the related art plasma lighting system causes channel interference of 7 channels or larger with a WLAN device. When the plasma lighting system is installed in an area where the WLAN device is in use, a channel must be necessarily set not to cause interference therebetween or the usage frequency band of the WLAN device must be moved to 5 GHz.
Meanwhile, conventionally, in order to improve an initial starting characteristics (or startability, activation) of the plasma lighting system, the plasma lighting system is sufficiently initially heated with a filament current in consideration of a change in temperature characteristics over time, and then voltage is applied to high voltage driving unit of the magnetron. However, the related art plasma lighting system does not have a function of regulating the amount of electron emission, having a problem in that interference with WLAN occurs. In addition, because the related art plasma lighting system does not make a difference between initial heating current and an operation current, noise generated from the plasma lighting system causes communication interference with the WLAN.